The 4-Hour Flight and Fiery Re-Entry That Could Give NASA Its Mojo Back Page 24

November 2014

ORION The 4-hour flight and fiery re-entry that could give NASA its mojo back page 24

Proactive on cybersecurity/page 30 Earth-observing Sentinels/page 34 Aireon’s Thoma on airliner surveillance page 22

A PUBLICATIONPUBLICATION OFOF THETHE AMERICANAMERICAN INSTITUTEINSTITUTE OFOF AERONAUTICSAERONAUTICS ANDAND ASTRONAUTICSASTRONAUTICS Preparing to install Orion’s heat shield at Kennedy Space Center in anticipation of its Dec. 4 liftoff.

26 AEROSPACE AMERICA/NOVEMBER 2014 TIME TO FLY

If NASA is going to deliver astronauts to Mars or an asteroid, Lockheed Martin is designing the crew capsules that will take them there. The Orion project has been unfolding for years in board rooms and cleanrooms, but things will get real on Dec. 4 when an unmanned test version blasts off from Florida. Natalia Mironova describes the road to Exploration Flight Test-1 and the technical challenges to come.

f all goes as planned, an unmanned could become a problem as NASA closes in Orion multipurpose crew vehicle will on the first crewed launch in 2021. splash down in the Pacific Ocean For Lockheed and NASA, the stakes on southwest of San Diego on Dec. 4, hav- Dec. 4 could not be higher. A smooth mis- ing ventured 3,600 miles into space, sion would be a confidence builder that fartherI than any crew vehicle has gone since could shore up faith in the U.S.’ decision to the Apollo 17 mission in 1972. This early shelve its desire for a single-stage-to-orbit version of an Orion capsule will be coming space plane in favor of a simpler capsule back hot because of a trajectory designed to and rocket approach. partially mimic a deep-space mission. The A maxim among engineers is that tests craft will plow into the atmosphere at 6.8 like EFT-1 are designed to find problems. No miles per second — that’s 80 to 85 percent of matter how things go, Orion advocates are the velocity of a trip back from the neigh- confident they’ll learn whatever technical borhood of the moon, where NASA plans to lessons will be required to ultimately suc- This artist concept shows Orion park an asteroid someday. The velocity will ceed. “If we do EFT-1 and the heat shield and its upper stage as they will appear in the Exploration Flight Test-1 mission. beat the 4.7 miles per second re-entry speed of the shuttle orbiters. The result will be melting-pot temperatures of 4,000 degrees Fahrenheit around some parts of Orion. To survive this, Orion will enter base first like an Apollo capsule and it will be protected in part by an updated version of the same protective foamlike Avcoat material that shielded the Apollo capsules. If following the Apollo template — but with a capsule 30 percent larger — was sup- posed to make it easy for NASA and Lock- heed to get to Exploration Flight Test-1, that has not been the case. Textron, the Avcoat provider, had to repair cracks discovered in NASA Orion’s heat shield in 2013 after a curing pro- cracks on us and we end up having a prob- cess. Lockheed Martin and NASA engineers lem because the heat shield failed, that’s ac- also had to change the shape of the capsule’s tually a good test because then we know launch abort aeroshell to reduce the aerody- the limits. We’ll have enough instrumenta- namic noise astronauts would hear during an tion on there to be able to understand what abort. Then there is the issue of spacecraft happened,” says Dan Dumbacher, a former mass: The EFT-1 version of Orion is within its NASA deputy associate administrator for ex- mass limit, but the Government Accountabil- ploration systems development and now a ity Office cautioned earlier this year that mass professor at Purdue University. By Natalia Mironova

AEROSPACE AMERICA/NOVEMBER 2014 25 back shell, which is possible because the back shell won’t be subject to as much heat. As with everything on Orion, mass was a big driver in the decision to use a combi- nation of these technologies. The heat shield’s foamlike Avcoat filler is fairly light, but the honeycomb framework and the titanium structure required to support it will bring the heat shield’s weight to 4,000 pounds — that’s on average 39 pounds per cubic foot compared with the tiles on the exterior of the shuttle orbiter that weigh 13 pounds per cubic foot. Using both technologies — Avcoat and the tiles — made for a lighter overall thermal protection system. “If you are lighter you Sources: NASA, Lockheed Martin, US Navy can go further for the same amount of pro- pellant,” explains Price. Launch illustrations by Anatoly Zak Relying on a familiar heat-shield mate- Survival plan rial had its advantages, but it also has The attraction of Apollo was the shape’s brought its share of challenges. Avcoat is a proven ability to handle high-speed re-en- mixture of epoxy and phenolic resins with tries. “We did look hard at other ideas, but it several types of glass fibers and phenolic turns out the physics are the same and the microballoons inside a glass-reinforced hon- shape still makes sense for this kind of mis- eycomb structure. On Orion, this is bonded sion,” says NASA’s Mark Geyer, the Orion to a titanium framework covered in carbon program manager. Once the engineers de- fiber sheets up to 2 inches thick. GAO in its termined that they would be using the basic 2014 “Assessments of Large-Scale Projects,” capsule shape of Apollo, they could draw on cautioned that thermal expansion during a actual flight data from the Apollo landings. flight could cause cracks to develop be- Engineers “have the benefit of all of that tween the “ablative material and the under- previous history — 12 or so full-scale re-en- lying shield structure.” tries,” says Larry Price, Lockheed’s deputy Textron says it used “Apollo proven program manager for Orion. techniques” to fix thermal expansion cracks At the top of EFT-1’s list of test objec- that developed during curing, and that no tives will be to evaluate its thermal protec- cracking was found after stress tests on the tion system, which borrows from Apollo and Avcoat and its carrier structure. also the space shuttle program. When Orion plows into the atmosphere, it will be protected by a dish-shaped, multilayered heat shield covered by Avcoat, an updated recipe of the ablative, or meltable, material that protected the Apollo capsules. Unlike Apollo, Orion will have shuttle-de- rived protective tiles instead of Av- coat on its conical Sources: NASA, Lockheed Martin, US Navy

26 AEROSPACE AMERICA/NOVEMBER 2014 withstand extreme pressure loads. Even with all the efforts to shave mass, the GAO cautions that Orion is 2,800 pounds over the cur- rent maximum take- off limit of 73,500 pounds for the next Orion launch, an unmanned flight called Exploration Mis- sion-1 planned for 2017. “The mass of the spacecraft re- Sources: NASA, Lockheed Martin, US Navy mains a top program risk,” GAO says in its annual assessment. A separate concern is that micro-cracks EM-1 will be the first flight of Orion on the could develop within the Avcoat because of new Space Launch System rockets, and GAO the long-term exposure to deep space. says NASA plans to solve the mass problem These micro-cracks ultimately were not a by relying on the performance of SLS and problem for Apollo or later missions, but adjusting the load, mission duration and size Orion will be in the cold of space longer of the crew on future crewed flights. and will re-enter hotter. Lockheed says it is fully aware of the Lockheed doesn’t expect micro-crack- mass issue. “For Exploration Mission-1, we ing to be a problem during EFT-1 because, have a design that closes on mass, however at just over four hours, the flight won’t be we have identified some threats to that plan. long enough to subject Orion to extreme Those threats are typical for a spacecraft de- cold, and the company says it is looking at velopment program and we do not anticipate “potential modifications” to prevent micro- any issue meeting the mass requirement,” cracking on longer missions. But it’s impos- says Carol Martin, Lockheed Martin’s Orion sible to perfectly recreate deep space in a Exploration Mission director, by email. lab, so engineers will still be interested in inspecting the shield for signs of cracks after Whisking astronauts to safety the December test flight. “We want to gather Re-entry is risky, but so is launch. A detach- data in flight and see how Avcoat performs at 4,000-nautical-mile entry as well as future flights and determine if the cracking is a problem or not,” says Price, who describes Avcoat as a brittle material. “There is a strong belief that as the material melts and ablates away, it would fill any of those micro cracks,” he says. In the end, the team had to compromise to pick the best thermal protection material that was structurally solid and worked within the weight limitations. “Nothing is perfect.”

Weight watching Mass limits are hot on the team’s mind too. Orion’s pressure hull, for example, is made from aluminum lithium alloy — the same material used to build the shuttle’s external tanks — because it is lightweight yet able to Sources: NASA, Lockheed Martin, US Navy

AEROSPACE AMERICA/NOVEMBER 2014 2527 able system of solid rocket motors and an aeroshell will ride atop Orion during ascent and will pull the capsule away from an exploding or out of control Space Launch System vehicle. The GAO warns that a funding shortfall has pushed the next test of the abort system to 2018, which might not leave enough time to fix any problems before the first crewed flight planned for 2021. The launch abort system won’t be fully operational in the December test. The first abort test in May 2010 became something of an Internet video sensation. The Orion mockup is seen soaring a mile into the air. If humans The launch abort system is lowered by crane for installation had been aboard, they would have experienced a jolt of 15 Gs that would on the Orion spacecraft for push them deep into their seats and make it difficult to move and even Exploration Flight Test-1 inside breathe for the 4.5 seconds of the abort motor burn. A variable-thrust atti- the Launch Abort System Facility, at NASA’s Kennedy Space Center. tude control motor keeps the stack correctly oriented until a jettison motor pulls the launch abort system off the crew module so the capsule can de- ploy its three parachutes. The 2010 test “was almost perfect. It’s a very big deal,” says NASA’s Geyer. “All three of those motors had to work perfectly, the parachutes had to work, and it worked like a charm.” Engineers learned a valuable lesson from a static test with the abort motor. The noise inside the capsule would have been excessive for the astro-

Sources: NASA, Lockheed Martin, US Navy

Sources: NASA, Lockheed Martin, US Navy NASA

2826 AEROSPACE AMERICA/NOVEMBER 2014 nauts, so NASA and Lockheed decided to bend the walls of the aeroshell into a curved ogive shape. The 2018 flight would be the first abort test of the new shape. If something goes wrong during the launch in December, there will be no saving Orion, since it will fly with an inert abort and attitude control motor. Only the jettison motor will be operational because it must remove the aeroshell and stack from Orion once it is through the atmosphere.

On the inside The similarities to Apollo are obvious but mostly skin deep for Orion. “On the outside it may look like an Apollo spacecraft, but on the inside it’s nothing at all like Apollo,” NASA Administrator Charles Bolden told Sources: NASA, Lockheed Martin, US Navy Aerospace America earlier this year. Orion’s interior will draw from the best of the computing revolution sparked in part tion, vibration and high temperature re- by the technology investments of the Apollo quirements of deep-space travel, according program. “If you look at a picture of the to Lockheed Martin’s Orion avionics direc- Apollo control panel — it’s fascinating — you tor, Paul Anderson. Some of the test flight see a lot of buttons and switches. So that’s objectives include learning how this new how they controlled things, through computer system will perform under the switches. Ours is now automated; it looks stresses of Van Allen belt radiation and high- like a touch screen that you see with the speed re-entry. fancier computers today and the crew can One aspect that will always be challeng- go through their critical procedures, do all ing for the crew on a long mission is the vol- their commands with those screens,” says ume of Orion. On a lunar-class mission, an Geyer. Though they look like touch-screen Orion crew of four might have to spend up to panels, the crew members on future flights 21 days in a space measuring 305 cubic feet will use a mouse-like device in their seats or — about twice the passenger volume of a Ford buttons along the side of the three panels to Explorer and eight times smaller than the access the computer. This will avoid acci- 2,625-cubic-foot crew compartment of a dental pressing of touch-screen buttons by seven-crew-member space shuttle orbiter. random objects floating around. That’s not as small as it sounds, suggests The crew interface system won’t be Geyer: “The great thing about zero G [is that] used much on a mission that goes smoothly. once you get into space you can use the ceil- Even the launch abort system was initially ing. Normally on the ground there is all this intended to be autonomous or triggered by unused space, but you’re floating around and mission control. Astronauts asked for and so it’s actually much bigger volume when you have received the ability to trigger it, one are in zero G because people can be on the contractor says. ceiling, on the floor, on the sides. You get to These crew interface panels won’t be use the space much more efficiently.” flying during EFT-1. Mass simulators will be The truth is that squeezing astronauts used instead. The vehicle management com- into an Orion is a problem that many at NASA puter — the avionics system supplied by are anxious to have. As much as anything Honeywell Aerospace — will be fully opera- EFT-1 will be a tangible step in that direction. tional though. The VMC is a single electron- “If we’re actually going to do this, if ics unit composed of four computer mod- we’re actually going to push out beyond the ules that execute flight control and connect moon and try to go to Mars, it will take dar- to the communication and tracking equip- ing. It will not be something for the timid,” ment. The system is similar to the one cur- says NASA’s Todd May, program manager for rently flying on the Boeing 787 Dreamliner the Space Launch System. aircraft, beefed up to withstand the radia- Ben Iannotta contributed to this report.

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